New Machine Build- It is about time I get this mill started

[antichip]

Well I am about ready to start ordering materials for my self built mill.
It will have a working envelope of the 3X2 foot table with a 2.5 foot z travel. I may have to add a little to this before it is all said and done. Main frame will be 6" square tube .5" thick wall of an undetermined alloy. Any thoughts? I considered a stainless alloy for main base rails.
I am scared of resonance so I will fill the tubing with an asphalt based material.
Everything will be machined to as near square and flat as I can then welded. These components will then get sent for stress relief and final grinding. Come back for drilling pinning and bolting.
I will get the little machine shop spindle replacement unit.
I will use the most accurate rails and ground screws I can get. To get a more accurate screw a little cheaper I will spin the nut and use whatever I find in my application range, length and accuracy wise.

I do not know what to use for my motive forces yet. I have a linistepper drive coming and will play with that on the 8x14 lathe, but I think this mill will do some decent cutting, and I want motion control to match to the specs of the frame.

I have a feeling I am going to have to add another motion stage for the tool changer.


Anyone know of a good grinding shop in the Tampa bay area?

I will update the design as it progresses.


Here is a more detailed table drawing.

This will be one welded structure. The raised datum edges are clear in this view.

[antichip]

I called and was quoted a price of nearly 800 dollars for the 20 foot section of 6"X6" Steel tube .5" wall thickness.

I was a little stressed over the cost of the steel today. I asked a few people and looked at a couple other types of machines built with 4x4x.25 tube.

So I decided I will be using .25" wall 6x6.


There was a machine shop or 2 closing around here with stock for sale. I will look into that tomorrow.

As designed before with .5" wall tube weight would have been around 1800-2000lbs just for the frame unit. That also scared me a little. But as a benefit, that is the stationary mass. My weight load per axis should be real reasonable.

I will also get info on the grinding job tomorrow, and we will see what the bill will be for that.

[antichip]

Well a couple months later and I am rethinking this. I have aquired many many parts, but not nearly enough to get actually started. I have 5 32 inch rails and 5 sr15 trucks. I will order more trucks so I have 2 per rail. I also got 5 us digital linear encoders, but they are only 360 lines per inch. 7 tenths that would make with quadrature encoding right? These were part of a medical aiming device at one point. I was hoping to be able to use the connected pmd based board ( http://www.pmdcorp.com/advanced-moti...ontrol-ics.cfm ), but I have yet to make serial contact with the board. They would be nice as they would allow for near direct use of the current hardware. The unit also had a very set of laser line generators. Very clean lines. I will use 2 for x-y positioning and maybe one on the side for a rough z measure. I also have about 100 misc steppers in the 100 oz range.

Actually the amount of stuff I aquired over the last 2 months is no less than amazing. Computers for all 4 machines. I added a x2 and a HF 4x5 micro lathe to the shop.

My issue is that I am trying to do this on a very limited budget as we all are. but I am making progress.